KVM: s390: base hrtimer on a monotonic clock

KVM: s390: base hrtimer on a monotonic clock

commit 0ac96caf0f9381088c673a16d910b1d329670edf upstream.

The hrtimer that handles the wait with enabled timer interrupts
should not be disturbed by changes of the host time.

This patch changes our hrtimer to be based on a monotonic clock.

Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Acked-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
[bwh: Backported to 3.2: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>